The present invention relates broadly to fittings for directing fluid flow through hulls, bulkheads or other fluid impervious walls and, more particularly, to a two-piece hull fitting having an internally threaded conduit member and an externally threaded corresponding retainer for fitment to a preformed opening in a hull, bulkhead or other fluid impervious wall wherein the volumetric flow rate of any fluid passing therethrough is maximized relative to the size of the preformed opening.
In the past, two-piece hull fittings have typically included a hollow, threaded member having a flange formed at one end thereof for abutment to a hull when the conduit is passed through a preformed opening therein. A threaded nut-like member is attached to the conduit on the other side of the hull and tightened thereagainst, forming a seal on both sides of the hull. Hoses are typically attached to one end or the other to direct fluid flow through the hollow conduit. Typically, the diameter of the passageway formed the hollow conduit is substantially less than the diameter of the preformed opening in the hull. This results in fluid flow at a volumetric flow rate which was less than that which could be achieved through the preformed opening without a fitting.
One example of such a fitting is found in Medvick U.S. Pat. No. 4,828,296. There, a fluid coupling is provided having a substantially constricted flow passageway relative to the required bulkhead opening. Rogers U.S. Pat. 4,234,218 offers another example.
The above patents are indicative of another problem with hull fittings, namely, complicated mounting structures. The Medvick patent discloses a hull fitting using numerous parts. Other complicated hull fittings are illustrated in Lawrence et al U.S. Pat. No. 5,129,684, Bunnell et al U.S. Pat. No. 4,224,464 and a Greene U.S. Pat. No. 3,749,424. All disclose fittings having a multiplicity of constituent parts.